1. The present invention relates to a method of dispensing a carbonated liquid, especially a beverage, into a container, such as a bottle, under counterpressure, whereby the introduction of the liquid, which is under a filling pressure, into the container, which is in a sealing position with a filling element, is effected during a filling phase that follows pressurizing of the container, whereby return gas displaced by incoming liquid is withdrawn from the container, at least for a while, via a return gas passage of the filling element, and whereby after termination of the filling phase with the container still in a sealing position with the filling element, first a pre-relief of pressure in the container to a pre-relief pressure is effected in a pre-relief phase, and subsequently a relief of pressure in the container to atmospheric pressure is effected. The present invention also relates to an apparatus for carrying out this method, with the apparatus including: a liquid chamber for the liquid that is to be dispensed; at least one filling element, with which a respective container that is to be filled is brought into a sealing position at least during pressurizing of the container, a filling phase, and first a prerelief of the pressure of the filled container to a pre-relief pressure, and subsequently a relief of the pressure of the filled container to atmospheric pressure; a filling channel that is provided on the filling element and that is adapted to communicate with the liquid chamber via a controlled liquid flow valve; a return gas passage formed on the filling element for return gas that is displaced from the container during the filling phase and/or that flows off during relief of the container; and a chamber that includes outlet means to the atmosphere and that communicates with the return gas passage at least during the pre-relief phase, which follows the filling phase.
2. Description of the Prior Art
When carbonated liquids, especially beverages, are dispensed under counterpressure into containers, such as bottles, it is necessary after termination of the liquid introduction, i.e. the filling phase, to relieve the pressure of the container to atmospheric pressure. With liquids, such as champagne or soft drinks, that already due to their relatively high CO.sub.2 content have no ideal filling properties, and in particular especially when these liquids are to be dispensed at relatively high temperatures for economical reasons, it is necessary to carefully relieve the pressure in such a way that foaming up or over of the dispensed liquid is avoided. For this purpose, it is known to undertake the relief to atmospheric pressure in stages such that a pre-relief phase precedes the actual relief of pressure to atmospheric pressure.
With one known method of this type (German Auslegeschrift 11 27 241 Quest dated Apr. 5, 1962), at the conclusion of the filling phase, the gas volume present in the filled container is briefly released to the atmosphere, and in particular by briefly opening a relief valve provided on the filling element via a cam of the filling machine, and immediately thereafter again closing this valve, so that as a result of the thereby occurring relief of the gas volume of the container to a lower pressure value, the carbon dioxide that is not fixedly contained in the dispensed liquid can escape and the dispensed liquid can become calm prior to the final relief to atmospheric pressure and the withdrawal of the container from the pertaining filling element. However, one of the drawbacks of this heretofore known method is that a pre-relief to a defined and also always constant pre-relief pressure cannot be achieved, which is a necessary precondition for an economical bottling at maximum capacity or efficiency. Since with the known method the brief opening of the relief valve of the filling element is effected by a cam, it is in principle also not possible to adapt the pre-relief to liquids having different filling characteristics.
Also known is a method of dispensing carbonated liquids under counterpressure into containers with the aid of a single-chamber counterpressure ,filler (German Offenlegungsschrift 36 22 807 Schadel et al dated Jan. 21, 1988). With this method the filling phase is terminated, by closing the liquid flow valve of the pertaining filling element, when a liquid level is reached in the container where the lower end of a return gas tube extends into the dispensed liquid. After conclusion of the filling phase, i.e. after closing of the liquid flow valve, the return gas tube is connected with an annular chamber that has a pressure that is less than the pressure that exists in the liquid chamber, so that the liquid that is above the lower end of the return gas tube is conveyed off out of the bottle, through this return gas tube, and into the annular chamber. The object of this measure is to correct the filling level obtained at the conclusion of the filling phase to a predetermined desired height; this measure is not a pre-relief of the respective container.
It is therefore an object of the present invention to provide a method and apparatus with which in an economical manner even liquids having very different filling characteristics can be optimally dispensed, and in particular via an optimum adaptation of the pre-relief pressure to the filling characteristics of the respective liquid that is to be dispensed in such a way that it is possible to work with as low a pre-relief pressure as possible, yet during the relief of the pressure to atmospheric pressure, a foaming of the dispensed liquid as well as an escape of this liquid out of the container can be avoided via channels of the filling element.